| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the conventional problems that deposition of mist to an optical component causes the deterioration in detection accuracy when droplet ejection status detection is performed using a laser beam. <P>SOLUTION: An LD unit 202 has an LD 201 housed in covers 222, 223. An aperture 212 having an opening 212a is provided in a part to be emitted by the laser beam. An air flow 225 introduced from an introduction part 224 is ejected from the opening 212a emitting the laser beam, thereby preventing the mist from entering the LD unit 202. <P>COPYRIGHT: (C)2012,JPO&INPIT |
